SEP、EMG监测在腰骶部椎管内病变术中的应用

目的：探讨体感诱发电位（SEP）及肛周肌电图（EMG）监测在腰骶部椎管内病变显微切除术中的作用和疗效评价。方法：对75例患者进行显微手术切除腰骶管病变术中作胫后神经刺激，在相关头皮记录SEP和腰骶部脊神经所支配的肛门外括约肌作EMG监测，并与麻醉后、手术开始前的记录进行比较。术中SEP以潜伏期延长10％或波幅下降50％作为预警信号，EMG以出现异常高电压作为预警参考值。结果：75例患者中，62例（83％）术中SEP监测异常者于病变切除后潜伏期缩短超过5％和（或）波幅上升超过20％；10例（13％）无明显变化；仅3例SEP监测显示潜伏期延长和波幅下降，术中均作成功预警，调整手术策略后，1例恢复至术前水平，2例明显改善。55例（73％）患者术中肛周EMG记录到不同程度的异常高电压，均根据情况调整手术方案。结论：腰骶部椎管内病变切除术中应用SEP、EMG监测可以预防和减少神经损伤，并能对手术疗效进行即时评价。

The roles of intra-operative SEP and crissum EMG monitoring of the microsurgery and evaluation operative effects in patients with lumbosacral spinal canal lesions

Objective：To explore the roles of intraoperative SEP and crissum EMG monitoring in the microsurgery in patients with lesions of lumbosacral spinal canal. Methods： Seventy-five patients with lesions of lumbosacral spinal canal were analyzed, stimulating their posterior tibial nerves,recording the cortical SEP of centre and crissum EMG intraopearation the results were compared with that between post-anesthesia and pre-opration. The decrease of SEP amplitude less than 50% of naomal potential, the prolongation of the latency less than 10% and EMG withour strong evoked discharge were within the safe range. Results：Sixty-two cases（83%） were obversed with shortening of latency by more than 5% and/or rising of amplitude by more than 20% in SEP monitoring, 10 cases（13 % ） showed no changes and 3 cases showed prolonged ltent phase and fallen of amplitude during surgery, in which one case recovered to the level of pre-opration and the other two were improved after adjusting of operating strategies. Abnormal discharges of crissum EMG were recorded in 55 cases （73%）, and adjustment was made according to the changes. Conclusion： Intra operative SEP and EMG monitoring may protect nerves from injury and provide evaluation to curative effect of patients with lumbosacral spinal canal lesions after sugery in time.